How do young children learn to use symbols to stand for objects? The goal of the proposed project is to explore mechanisms underlying children's early ability to understand and interpret non-verbal symbols. In symbol and its referent on young children's ability to achieve this symbol-referent mapping. Of particular interest is how the influence of iconicity may change over development. A review of the existing literature raises the counterintuitive possibility that iconicity exerts a greater influence on children's symbol interpretation later in development than at its onset. Four experiments are proposed. Each is designed to assess how iconicity influences children's symbol interpretation at 18 and 26 months of age. The first experiment tests the hypothesis that younger children's success at grasping the relation between a symbol and its referent may be relatively unaffected by the iconicity of the symbol whereas older children may benefit from iconicity in symbol interpretation. The second experiment examines how the "dual representation" challenges of being able to construe three-dimensional objects as both objects and symbols mediates the influence of iconicity. The third experiment is designed to assess whether the influence of iconicity on symbol acquisition is a product of semantic relatedness more generally, as opposed to the physical resemblance between symbol and referent per se. The fourth experiment assesses whether developmental changes in the use of iconicity may be driven by developmental differences in children's familiarity with the conventionalized icons employed in our culture. These experiments explore potential mechanisms by which iconicity might affect symbol interpretation, and attempt to uncover some of the processes driving developmental change in symbol acquisition. This work informs not only symbol acquisition in typically developing children, but also the effectiveness of various augmented communication techniques employed with language- impaired and developmentally disabled populations.